There is no doubt in my mind that cats vary in intelligence just as much as humans do. We all like to think our own children and cats are the most intelligent, but it just ain't so. It sounds like Simon is in the genius range of cat IQs. I have had bright cats and stupid cats. Of my current three Dushka is the most intelligent (though as Persil is still small I am not 100% sure) but Ellie is my 'special' cat - I seriously think she is not all there. I love her anyway, and Persil adores her. So just marvel at Simon and enjoy him, and give him lots of challenges like you would a gifted child!